Vitamin D3 deficiency may occur in individuals with limited exposure to sunlight or inadequate dietary intake of Vitamin D3.

• Cholecalciferol is necessary for proper absorption of calcium and phosphate, which are essential for maintaining healthy bones and teeth and for preventing rickets, osteomalacia, and osteoporosis.
• It also plays an important role in reducing the risk of pre-eclampsia during pregnancy and breastfeeding, supporting healthy growth in infants.
• Cholecalciferol contributes to strengthening the immune system.

The biologically active form of Vitamin D3, calcitriol, acts by binding to Vitamin D receptors (VDRs) that are widely present in various tissues of the body. Being fat-soluble, Vitamin D3 has an approximate half-life of 50 days. It is absorbed from the small intestine, binds to specific α-globulins, and is transported to the liver, where it is converted into 25-hydroxy Vitamin D3 (calcidiol). A further conversion in the kidneys produces 1,25-dihydroxy Vitamin D3 (calcitriol), which enhances calcium absorption. Unmetabolized Vitamin D3 is stored in tissues such as fat and muscle, and is eventually excreted through feces and urine.

For capsule: Adults:

• Treatment of Vitamin D3 deficiency: 40000 IU once weekly for 7 weeks. Doses for maintenance therapy is 1400–2000 IU/day. To confirm the target level of 25 hydroxyvitamin D, measurement of it should be determined 3–4 months after initiating the maintenance therapy.
• Prevention of Vitamin D3 deficiency: 20000 IU every 4 weeks. Higher doses may be required in certain situations.
• Addition to specific therapy for osteoporosis: 20000 IU once a month.

For capsule: Children (12–18 years):

• Treatment of Vitamin D3 deficiency: 20000 IU once every 2 weeks for 6 weeks.
• Prevention of Vitamin D3 deficiency: 20000 IU every 6 weeks.

For film-coated tablet: 1000 IU (1–2 tablets) daily, or as directed by physician. Take the medicine with food or within 1 hour after a meal.

For oroflash or chewable tablets: 1000 IU to 2000 IU daily, or as directed by physician. Take the medicine with food or within 1 hour after a meal. Place the tablet in mouth swallow after chewing.

For Oral Solution:

• Up to one year: 400 IU once a day or as directed by the physician.
• 1 year to 18 years: 600 IU once a day or as directed by the physician.

Injection: For treatment-

• Rickets: 1 ampoule every 2 weeks for one month then 1 ampoule for every 4 months
• Osteoporosis: 1 ampoule every 2 weeks for 3 months
• Osteomalacia: 1 ampoule every 2 weeks for 3 months
• Tetany caused by hypocalcaemia: 1 ampoule for every 4 months which may be increased to 2 ampoules
• Menopause: 1 ampoule for every 6 months
• Vitamin D3 deficiency: 1 ampoule can be repeated 1 to 6 months later

Injection: For prevention-

• Pregnancy: 1/2 ampoule at 6th or 7th months
• During breastfeeding: 1/2 ampoule for every 6 months
• Children up to 5 years: 1 ampoule for every 6 months
• Adolescent: 1 ampoule for every 6 months
• Elderly Dosages: 1/2 ampoule for every 3 months.

Direction of use of Injection-

For oral use-

• Step-1: Place the thumb on ampoule and break the upper narrow part of the ampoule.
• Step-2: Pour out the solution of the ampoule in a spoon.
• Step-3: Mix the solution with water or milk before oral use.

For IM use-

• Step-1: Place the thumb on ampoule and break the upper narrow part of the ampoule.
• Step-2: Then use as IM injection.

Vitamin D3 should not be used in conditions associated with hypercalcemia. It is also contraindicated in individuals with known hypersensitivity to vitamin D3, similar compounds, or any of the formulation components. Additionally, it should be avoided in cases where there is evidence of vitamin D toxicity.

Nutritional supplements are generally considered safe and well tolerated. However, adverse effects may occur, particularly in cases of excessive intake leading to hypercalcemia or vitamin D toxicity. Acute symptoms may include loss of appetite, headache, nausea, vomiting, abdominal discomfort, and constipation.

Studies indicate that doses up to 4000 IU may be used safely during pregnancy. The usual recommended daily intake is around 400 IU, although higher doses may be required in vitamin D–deficient women. Pregnant women should follow medical advice based on individual needs and response to therapy.

Vitamin D3 and its metabolites are excreted into breast milk. Although toxicity in breastfed infants has not been reported, caution is advised, and total vitamin D intake (including maternal supplementation) should be considered.

Regular monitoring of plasma calcium levels is recommended in patients receiving high doses of vitamin D3, especially in those with renal impairment and during pregnancy or lactation. Patients taking digoxin or thiazide diuretics should consult a healthcare provider before supplementation. Individuals with liver or kidney disease, primary hyperparathyroidism, lymphoma, tuberculosis, or granulomatous disorders should also seek medical advice prior to use.

Excessive intake of vitamin D can lead to hypercalcemia, which is the most serious consequence of toxicity. Symptoms may include nausea, vomiting, frequent urination, loss of appetite, weakness, fatigue, thirst, and constipation. Chronic toxicity may result in calcification of blood vessels and organs. Management involves discontinuation of vitamin D intake and adequate hydration.

Vitamin in bone formation, Vitamin-D preparations

Store in a cool (below 25°C), dry place, protected from light. Keep out of reach of children.